The present invention relates generally to apparatus for determining the shoulder angles of horses as an aid in proper shoeing, and more particularly such apparatus utilizing cup means for locating the measuring apparatus relative to the shoulder bone knot.
The hoof of the horse is a massive structure of keratinous tissue, corresponding to the nails and claws of other animals, which being without nerve endings and being abradable, is well adapted by the process of continuous growth and abrasion to be worn into a desirable or optimum configuration with respect to ground contact angle of the hoof for the particular horse, depending upon its weight, conformation, and preferred gait.
It has been known since ancient times that the load carrying and pulling capacity a of horse can be greatly increased by providing additional traction or grip at the hoof to ground contact. Therefore, the horse shoe as it is presently known has developed over the centuries, for the purposes of increasing the traction force exerted on the ground by the horse's muscular efforts, and to prevent hoof abrasion.
Because horse shoes are not abradable to adapt themselves to appropriate or optimum ground contact angles for particular horses, the horseshoes must be so mounted, for good results, as to be well-adapted to provide the desired ground contact angle in accordance with the conformation, weight and gait of a particular horse. This problem has long been known, and farriers and shoeing smiths have long known that it is preferrable to so shape and mount the shoe that the angle of the forefoot is parallel to the angle of the shoulder bone. Gauges for measuring hoof or forefoot angles have long been known, but the proper determination of correct hoof or forefoot angle with respect to the shoulder angle, has been dependent upon estimations involving guesswork. Prior shoulder angle measuring devices are described at page 100 of "Horseshoeing Theory and Hoof Care" by Dr. Niles Van Hoosen, et al. Such devices require considerable skill in the estimation of the run of the shoulder bone and in gauge manipulation, and have therefore not found wide acceptance.